Molding apparatus



L. L. JOHNSTON Aug. 30, 1960 2,950,511

MOLDING APPARATUS Filed Sept. 5, 1957 3 Sheets-Sheet l Fig.i.

INVENTOR Loyal L. Johnson j Aug. 30, 1960 L. L JOHNSTON Momma APPARATUS 3 Sheets-Sheet 2 Filed Sept. 5, 1957 Fig.

Aug. 30, 1960 L. L.. JOHNSTON MoLnING APPARATUS 5 Sheets-Sheet 3 Filed Sept. 5, 1957 INVENTOR Loygl L. Johnston Patented Aug. 36, 1960 if A am e ai 2,950,53lil MLDMG APPARATUS 5 Loyal L. Johnston, Zelienople, Pa., assigner to Herman Pneumatic Machine Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Sept. 5, 1957, Ser. No. 632,252

2 Claims. (Cl. 22-l6) This invention relates to molding apparatus and particularly to apparatus which is adapted to be used :for the formation of molds out of nely divided mold forming material and the production of castings in such molds, especially by fentrifugal casting. The invention has to do particularly with improved means for retaining mold forming material in a flask or asks.

The present invention may be applied to apparatus for forming molds for centrifugal casting of the type shown in my Patent No. 2,449,900. Such apparatus comprises either one flask or a plurality of flasks in a battery; for simplicity I shall here refer to one flask. The ask is rotatably carried by a cradle which in turn is mounted for movement between a position in which the axis of the flaslr is generally upright and a position in which the axis of the flask is generally horizontal. The cradle carries means for rotating the ask. At the beginning of the cycle the ilask is disposed in generally upright position and its lower end is closed by mold forming material retaining means whereupon finely divided mold forming material, such, for example, as sand, is introduced into the flask through the upper end thereof. The liask may be rotating relatively slowly or not rotating while the mold forming material is being introduced. Rotation of the ask is commenced if the flask has been stationary during introduction of the mold forming material and the liask is moved to generally horizontal position. The mold forming material retaining means is moved to inoperative position, a mandrel is introduced into the flask to compact the mold forming material, the mandrel is withdrawn and molten material, for example, iron, is then introduced into the mold and centrifugally cast to make, for example, a length of soil pipe. After the casting has solidified the flask is returned to its generally upright position and the casting is ejected therefrom whereupon the mold forming material retaining means is again disposed in its operative position to close the lower end of the aslt and the cycle is repeated.

I provide mold forming material retaining means of novel form mounted and operated in novel manner whereby unprecedentedly eicient operation of the apparatus is promoted. Iv mount a mold forming material retainer on the cradle and I also mount on the cradle means for moving the mold forming material retainer between an operative position closing an end of the ask and an inoperative position away from the end of the flask. Prefera ly the mold forming material retainer is pivotally mounted on the cradle to turn about an axis extending generally transversely of the axis of the flask and means are provided for turning the mold forming material retainer about that axis between an operative position closing an end of the flask and an inoperative position away from the end of the flask and generally at the side of the flask. Desirably the operating means, i.e., the means for turning the mold forming material retainer in its movement between operative and inoperative positions, includes a rack and pinion. I preferably employ a exible coupling between the operating means `and the retainer.

I prefer to utilize a plurality of asks disposed in generally side-by-side relation each rotatably carried by the cradle together with means carried by the cradle for rotating the flasks, mounting means, the cradle being mounted on the mounting means for movement between a position in which the axes of the ilasks are generally upright and a position in which the axes of the flasks are generally horizontal, means for so moving the cra'dle, a mold forming material retainer for each llask, the mold forming material retainers being pivotally mounted on the cradle to turn about a common axis extending generally transversely of the axes of the flasks, and means for simultaneously turning the mold forming material retainers about the common axis between operative positions closing an end of each aslc and inoperative positions away from the ends of the flasks and generally at the sides of the flasks, Each mold forming material retainer preferably has a pivotal connection with the cradle adjacent the corresponding flask and each such pivotal connection preferably includes a shaft to which the corresponding mold forming material retainer is fixed, the shafts being coaxial. Gperating means, preferably including a rack and pinion, are provided for turning the shafts, and exible couplings are desirably interposed between the operating means and the respective shafts. Turning of the shafts causes turning of the mold forming material retainers between operative positions closing an end of each flask and inoperative positions away from the ends of the flasks and generally at the sides of the liasks.

I preferably mount on the cradle a carrier for a mold forming material retainer together with means for moving the carrier between a position at an end of the ilask but somewhat spaced from the iiaslt and a position relatively remote from the end of the flask. The mold forming material retainer is carried by the carrier and is preferably movable relatively to the carrier in a direction which when the carrier is in its first mentioned position is generally parallel to the axis of the ask to a selected one of a plurality of positions to substantially close the end of the flask. The retainer is preferably carried by the carrier by means including screw means which are operable to move the retainer relatively to the carrier. The retainer preferably carries means substantially filling the end of the ilask and projecting into the end of the flask. Preferably the carrier has a generally cylindrical portion and the retainer a portion telescopingly associated with the generally cylindrical portion of the carrier, the retainer being movable relatively to the carrier to a selected one of a plurahty of positions to substantially close the end of the iiask. At least one of the telescopingly associated portions is preferably curved to permit relative angular adjustment between the retainer and the carrier.

Other details, objects and advantages of the invention will become apparent as the following description of a present preferred embodiment thereof proceeds.

In the accompanying drawings I have shown a present preferred embodiment of the invention in which Figure l is an end elevational view of molding apparatus, the mold forming material retaining means being shown in inoperative position;

Figure 2 is a side elevational view of the molding apparatus shown in Figure l, the mold forming material retaining means being shown in inoperative position in solid lines and in operative position in chain lines;

Figure 3 is a fragmentary elevational View, partly in vertical cross section and to enlarged scale, of a portion of the apparatus shown in Figure l but with the mold forming material retaining means swung to their downward or operative positions, the mounting means, cradle and asks being omitted for clarity;

Figure 4 is a fragmentary top plan view showing a portion of the mechanism shown in Figure 3;

Figure 5 is a vertical cross-sectional view takenron the line V-V of Figure 4;

Figure 6 is a vertical cross-sectional View taken on the -line VI-VI of Figure 5; v

Figure 7 is a fragmentary elevational view to enlarged scale and with a portion in vertical cross section of part of the lapparatus shown in Figure 2, the mold forming material retaining means being shown in operative position in solid lines and in inoperative position in chainv lines; and V n l Figure 8 is a plan view of the apparatus shown in Figure 7 but for clarity omitting the'showing of the flask end.

The apparatus shown is of the general type of that of my said patent. yI provide mounting meansV designated generally by reference numeral 2 in which is mounted a cradle 3 for movement between generally upright position and generally horizontal position as disclosed in my said patent. :In the drawings the cradle 3 is shown in generally horizontal position. Rotatably mounted on the cradle 3 are two parallel flasks 4 each driven through a belt 5 by a motor 6 also carried by the cradle. Parts of the apparatus not necessary to the =functioning of the invention are not shown.

The cradle 3 carries atop each of the asks 4 adjacent an end thereof a bracket designated generally by reference numeral 7, the two brackets being disposed side by side but spaced apart. 'Each bracket has opposed arms 8 spaced apart and reaching toward the end of the Viiask. Iournaled in the arms 8 of each of the brackets 7 is a shaft 9. Fixed to each shaft 9 is ta generally L-shaped arm 10. -Each arm 10 is fixed to the cor-responding shaft 9 at one end of the arm and whenV the y Each carrier 11 has a generally cylindrical 11 is disposed at a position relatively remote from the M Vend of the ask and alongside but substantially spaced from the flask.

Bolted to each carrier 11 by bolts 12 is a plate 13. vThreaded through 'the plate 13 yare three positioning screws 14 each provided with a lock nut 15 and adapted to be adjustably positioned so that their extremities 16 serve asstops or positioning members to precisely determine the position of a mold forming material retainer designated generally by reference numeral 17 and comprising a plate-like portion 18 welded as shown at 19 to a generally cylindricalportion 20 telescoping within the carrier 11. The outside of the generally cylindrical portion l20 is somewhat convexly formed or'curved as shown Vat 20a to permit relative angular adjustment between the retainer and the carrier. Three bolts 21 pass through openings 22 in the plate 13 and Iare threaded into the cylindrical portion 20 of the mold forming material retainer 17, the screws 14 and 21 being cooperatively operable to move the retainer 17 relatively to the carrier 11 in a direction which whenthe carrier is' in Yposition at an end of the iiask is generally parallel to the raxis of the flask to a selected one of a plurality of positions to substantially close the end of the ask. When the retainer 17 is in operative'positionthe face of the p'ortion 18 thereof opposed to the end of the flask just clears'theendiof the ilask by 'a very small fraction of an inch,A perhaps one-sixteenthY of-an inch, to permit turn- 2,950,511- l f c f f ing of the ask while the retainer does not turn, yet preventing the mold forming material in the flask from falling out. Alternatively, the retainer may be mounted in antifriction bearings so that it may turn due to frictional contact with the mold forming material. To pre vent substantial leakage of mold forming material while lling the flask and tilting it to generally horizontal position I preferably provide a projection 18a on the retainer which is of circular shape and of Very slightly smaller external diameter than the internal diameter of the extremity of the flask which substantially fills the end of the flask and projects intorthe end of the ask. The projection 18a may, for example, be a one-half inch thick circular plate Whoseexternal diameter is one-eighth inch less than the internal diameter of the extremity of the ask, providing a circumferential clearance between the projection .18a and the inside of the flask of one-sixteenth inch. Y g

Intermediate the upper portions of the asks the cradle carries a cylinder 23 arranged with its axis generally parallel to the axes of the flasks in which operates a piston with which is connected a piston rod 24 carrying at its outer end a toothed rack 25. The teeth 30'of the rack 25 point upwardly, the rack being supported upon a supporting and guiding roller 26 for back and forth movement as the piston is operated in the cylinder 23 by fluid under pressure controlled by suitable valves as well known to those skilled in the art.

llt has been explained above that thetwo shafts 9 are coaxial. Operatively interposed between the shafts 9 and connected with each thereof by a exible coupling 27 is a shaft 28 to which is fixed a pinion 29 in mesh with the teeth 30 of the rack 25. Thus movement of .the piston inthe cylinder 23 causes movement of the rack, which movement through the pinion 29`turns the shaft 28, which shaft'through theY flexible couplings 27 turns the shafts 9 to pivotally move the arms 10, car- -riers 11 and retainers 17 between operative and inopera- Vtive positions.

The ends of the arms 8 have upwardly facingpositioning faces 31 and the arms 10 carry lateral projections 32 having positioning stops 33 adjustably mounted thereon and adapted to come to rest upon the faces 31 `when the retainers 17 `are in operative position. 'Thus -the retainers can be quickly shifted between accurately disposed operative positions substantially closing the ends of the flasks and inoperative positions remote from the ends of the flasks permitting discharge of theV castings therefrom or permitting introduction of the mandrels fo compacting the mold forming material.

While I have shown and described a present preferred Yembodiment of the invention Vit is to be distinctly under- :tatably carried by the cradle, means carried by the cradle .for rotating the ask, mountingmeans, the cradle being mounted on the mounting means for movement between right rand a position in which the axis of the flask is-gen- .erally horizontal, means for so moving the cradle, a

Vcarrier for a mold forming material retainer `mounted on the cradle, means also mounted Von the cradlev for .moving the carrier between a position at an end of the .flask but somewhat spaced from the iiask and a position relatively' remote from the end ofthe flask, the'carrier having a generally cylindrical portion, and a mold forming material retainer having a portion telescopingly associated with the generally cylindrical portion of the'car- ;rier, the retainer being movable relatively'to the carrier to a selected one of aplurality of positions tosubstantially close' said end of the flask, atleast one of the telescopingly :associated portions being curved `to'p'ermit 5 relative angular adjustment between the retainer and the carrier,

2. Molding apparatus comprising a cradle, a flask 1'0- tatably carried by the cradle, means carried bythe cradle for rotating the flask, mounting means, the cradle being mounted on the mounting means for movement between a position in which the axis of the fiask is generally upright and a position in which the axis of the ask is generally horizontal, means `for so moving the cradle, Ia mold forming material retainer mounted on the cradle for movement between a position at an end of the ask but slightly spaced from the ask to retain mold forming material in the flask While the flask is rotating but While the retainer is stationary and a position out of alignment with the flask and means for so moving the retainer in which the retainer has a portion whose ex- 6 ternal diameter is very slightly smaller than the internal diameter of the extremity of the ask and which portion enters and substantially ills the end of the flask.

References Cited in the le of this patent UNITED STATES PATENTS 2,5,726 Campbell July 6, 1937 2,449,900 Johnston Sept. 21, 1948 2,613,410 Johnston Oct. 14, 1952 2,631,342 Romine Mar. 17, 1953 2,770,857 Boisson Nov. 20, 1956 2,822,162 Bastress Feb. 4, 1958 FOREIGN PATENTS 341,673 Great Britain Jan. 22, 1931 

